refractoring, refinement, improvement: part 2

JsonDiffPatch/AddOperation.cs

@@ -18,21 +18,17 @@ public AddOperation(JsonPointer path, JToken value) : base(path)
             Value = value;
         }
 
-        public override void Write(JsonWriter writer)
+        public override void Write(IJsonObjectWriter writer)
         {
-            writer.WriteStartObject();
-
-            WriteOp(writer, "add");
-            WritePath(writer,Path);
-            WriteValue(writer,Value);
-
-            writer.WriteEndObject();
+            writer.WriteOp("add").
+                WritePath(Path).
+                WriteValue(Value);
         }
 
         public override void Read(JObject jOperation)
         {
 
-            Path = new JsonPointer(SplitPath((string)jOperation.GetValue("path")));
+            Path = new JsonPointer(jOperation.GetValue("path"));
             Value = jOperation.GetValue("value");
         }
     }

JsonDiffPatch/CopyOperation.cs

@@ -18,21 +18,17 @@ public CopyOperation(JsonPointer path, JsonPointer fromPath) : base(path)
             FromPath = fromPath;
         }
 
-        public override void Write(JsonWriter writer)
+        public override void Write(IJsonObjectWriter writer)
         {
-            writer.WriteStartObject();
-
-            WriteOp(writer, "copy");
-            WritePath(writer, Path);
-            WriteFromPath(writer, FromPath);
-
-            writer.WriteEndObject();
+            writer.WriteOp("copy").
+                WritePath(Path).
+                WriteFromPath(FromPath);
         }
 
         public override void Read(JObject jOperation)
         {
-            Path = new JsonPointer(SplitPath((string)jOperation.GetValue("path")));
-            FromPath = new JsonPointer(SplitPath((string)jOperation.GetValue("from")));
+            Path = new JsonPointer(jOperation.GetValue("path"));
+            FromPath = new JsonPointer(jOperation.GetValue("from"));
         }
     }
 }

JsonDiffPatch/IJsonObjectWriter.cs

@@ -0,0 +1,15 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+using Newtonsoft.Json.Linq;
+
+namespace JsonDiffPatch
+{
+    public interface IJsonObjectWriter
+    {
+        void WriteProperty(string name, string value);
+
+        void WriteProperty(string name, JToken value);
+    }
+}

JsonDiffPatch/JsonDiffer.cs

@@ -9,9 +9,9 @@ namespace JsonDiffPatch
     /// <summary>
     /// Parts adapted from https://github.com/benjamine/jsondiffpatch/blob/42ce1b6ca30c4d7a19688a020fce021a756b43cc/src/filters/arrays.js
     /// </summary>
-    public class JsonDiffer
+    public static class JsonDiffer
     {
-        internal static string Extend(string path, string extension)
+        private static string Extend(string path, string extension)
         {
             // TODO: JSON property name needs escaping for path ??
             return path + "/" + EncodeKey(extension);
@@ -31,22 +31,22 @@ private static Operation Build(string op, string path, string key, JToken value)
                                     (value == null ? "null" : value.ToString(Formatting.None)) + "}");
         }
 
-        internal static Operation Add(string path, string key, JToken value)
+        private static Operation Add(string path, string key, JToken value)
         {
             return Build("add", path, key, value);
         }
 
-        internal static Operation Remove(string path, string key)
+        private static Operation Remove(string path, string key)
         {
             return Build("remove", path, key, null);
         }
 
-        internal static Operation Replace(string path, string key, JToken value)
+        private static Operation Replace(string path, string key, JToken value)
         {
             return Build("replace", path, key, value);
         }
 
-        internal static IEnumerable<Operation> CalculatePatch(JToken left, JToken right, bool useIdToDetermineEquality,
+        private static IEnumerable<Operation> CalculatePatch(JToken left, JToken right, bool useIdToDetermineEquality,
             string path = "")
         {
             if (left.Type != right.Type)
@@ -306,7 +306,12 @@ private static IEnumerable<Operation> ProcessArray(JToken left, JToken right, st
 
         private class MatchesKey : IEqualityComparer<KeyValuePair<string, JToken>>
         {
-            public static MatchesKey Instance = new MatchesKey();
+            public readonly static MatchesKey Instance = new MatchesKey();
+
+            private MatchesKey()
+            {
+
+            }
 
             public bool Equals(KeyValuePair<string, JToken> x, KeyValuePair<string, JToken> y)
             {
@@ -326,9 +331,9 @@ public int GetHashCode(KeyValuePair<string, JToken> obj)
         /// <param name="to"></param>
         /// <param name="useIdPropertyToDetermineEquality">Use id propety on array members to determine equality</param>
         /// <returns></returns>
-        public PatchDocument Diff(JToken @from, JToken to, bool useIdPropertyToDetermineEquality)
+        public static PatchDocument Diff(JToken @from, JToken to, bool useIdPropertyToDetermineEquality)
         {
-            return new PatchDocument(CalculatePatch(@from, to, useIdPropertyToDetermineEquality).ToArray());
+            return new PatchDocument(CalculatePatch(@from, to, useIdPropertyToDetermineEquality));
         }
     }
 

JsonDiffPatch/JsonObjectWriterExtensions.cs

@@ -0,0 +1,35 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+using Newtonsoft.Json.Linq;
+using Tavis;
+
+namespace JsonDiffPatch
+{
+    internal static class JsonObjectWriterExtensions
+    {
+        public static IJsonObjectWriter WriteOp(this IJsonObjectWriter writer, string op)
+        {
+            writer.WriteProperty("op", op);
+            return writer;
+        }
+
+        public static IJsonObjectWriter WritePath(this IJsonObjectWriter writer, JsonPointer pointer)
+        {
+            writer.WriteProperty("path", pointer.ToString());
+            return writer;
+        }
+
+        public static IJsonObjectWriter WriteFromPath(this IJsonObjectWriter writer, JsonPointer pointer)
+        {
+            writer.WriteProperty("from", pointer.ToString());
+            return writer;
+        }
+        public static IJsonObjectWriter WriteValue(this IJsonObjectWriter writer, JToken value)
+        {
+            writer.WriteProperty("value", value);
+            return writer;
+        }
+    }
+}

JsonDiffPatch/JsonPointerTokensSource.cs

@@ -0,0 +1,56 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+using Newtonsoft.Json.Linq;
+
+namespace JsonDiffPatch
+{
+    internal class JsonPointerTokensSource : IEnumerable<string>
+    {
+        private readonly IReadOnlyList<string> _list;
+        private readonly int startIndex;
+        private readonly int lastIndex;
+
+        public bool IsEmpty => lastIndex < startIndex;
+
+        public JsonPointerTokensSource(string pointer)
+        {
+            _list = pointer.Split('/').ToList();
+            startIndex = 1;
+            lastIndex = _list.Count - 1;
+        }
+
+        private JsonPointerTokensSource(IReadOnlyList<string> list, int startIndex, int lastIndex)
+        {
+            _list = list;
+            this.startIndex = startIndex;
+            this.lastIndex = lastIndex;
+        }
+
+        public string Last()
+        {
+            return lastIndex >= startIndex ? _list[lastIndex] : string.Empty;
+        }
+
+        internal JsonPointerTokensSource ForParent()
+        {
+            return new JsonPointerTokensSource(_list, startIndex, lastIndex - 1);
+        }
+
+        public IEnumerator<string> GetEnumerator()
+        {
+            for (int i = startIndex; i <= lastIndex; i++)
+            {
+                yield return _list[i];
+            }
+        }
+
+        IEnumerator IEnumerable.GetEnumerator()
+        {
+            return GetEnumerator();
+        }
+    }
+}

JsonDiffPatch/MoveOperation.cs

@@ -20,21 +20,17 @@ public MoveOperation(JsonPointer path, JsonPointer fromPath) : base(path)
             FromPath = fromPath;
         }
 
-        public override void Write(JsonWriter writer)
+        public override void Write(IJsonObjectWriter writer)
         {
-            writer.WriteStartObject();
-
-            WriteOp(writer, "move");
-            WritePath(writer, Path);
-            WriteFromPath(writer, FromPath);
-
-            writer.WriteEndObject();
+            writer.WriteOp("move").
+                WritePath(Path).
+                WriteFromPath(FromPath);
         }
 
         public override void Read(JObject jOperation)
         {
-            Path = new JsonPointer(SplitPath((string)jOperation.GetValue("path")));
-            FromPath = new JsonPointer(SplitPath((string)jOperation.GetValue("from")));
+            Path = new JsonPointer(jOperation.GetValue("path"));
+            FromPath = new JsonPointer(jOperation.GetValue("from"));
         }
     }
 }

JsonDiffPatch/Operation.cs

@@ -19,32 +19,7 @@ public Operation(JsonPointer path)
             Path = path;
         }
 
-        public abstract void Write(JsonWriter writer);
-
-        protected static void WriteOp(JsonWriter writer, string op)
-        {
-            writer.WritePropertyName("op");
-            writer.WriteValue(op);
-        }
-
-        protected static void WritePath(JsonWriter writer, JsonPointer pointer)
-        {
-            writer.WritePropertyName("path");
-            writer.WriteValue(pointer.ToString());
-        }
-
-        protected static void WriteFromPath(JsonWriter writer, JsonPointer pointer)
-        {
-            writer.WritePropertyName("from");
-            writer.WriteValue(pointer.ToString());
-        }
-        protected static void WriteValue(JsonWriter writer, JToken value)
-        {
-            writer.WritePropertyName("value");
-            value.WriteTo(writer);
-        }
-
-        protected static string[] SplitPath(string path) => path.Split('/').Skip(1).ToArray();
+        public abstract void Write(IJsonObjectWriter writer);
 
         public abstract void Read(JObject jOperation);
 
@@ -55,7 +30,7 @@ public static Operation Parse(string json)
 
         public static Operation Build(JObject jOperation)
         {
-            var op = PatchDocument.CreateOperation((string)jOperation["op"]);
+            var op = OperationCreator.Create((string)jOperation["op"]);
             op.Read(jOperation);
             return op;
         }

JsonDiffPatch/OperationCollection.cs

@@ -0,0 +1,34 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Text;
+
+namespace JsonDiffPatch
+{
+    internal class OperationCollection : IReadOnlyCollection<Operation>
+    {
+        private readonly List<Operation> _operations = new List<Operation>();
+
+        public int Count => _operations.Count;
+
+        public void Add(Operation operation)
+        {
+            _operations.Add(operation);
+        }
+
+        internal void AddRange(IEnumerable<Operation> operations)
+        {
+            _operations.AddRange(operations);
+        }
+
+        public IEnumerator<Operation> GetEnumerator()
+        {
+            return _operations.GetEnumerator();
+        }
+
+        IEnumerator IEnumerable.GetEnumerator()
+        {
+            return _operations.GetEnumerator();
+        }
+    }
+}

JsonDiffPatch/OperationCreator.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace JsonDiffPatch
+{
+    internal static class OperationCreator
+    {
+        public static Operation Create(string op)
+        {
+            switch (op)
+            {
+                case "add": return new AddOperation();
+                case "copy": return new CopyOperation();
+                case "move": return new MoveOperation();
+                case "remove": return new RemoveOperation();
+                case "replace": return new ReplaceOperation();
+                case "test": return new TestOperation();
+            }
+            return null;
+        }
+    }
+}